Smelting process



F. WST

SHELTING PRocEss Filed Oct March 18, 1930.

ffl/114717:: w52 t I c Patented Man i8. 1930 UNITED STATES PATENT" OFFICE -FRITZ -Wisn or DUSSELDORF, GERMANY SMELTING `:PROCESS Application led October-18, 1927, Serial No. 221,029, and in Germany August 6, 1926.

This invention relates in general to smelting processes and furnaces. and more particularly to furnaces for smelting or reducing iron that is poor in carbon.

5 In the reverberatory furnace described in the German Patent 315,264 it is not possible to increase the content of carbon in the smelted substance. Consequently it is not possible to smelt scrap iron or steel, such as iron chips, filings etc., for casting purposes in this furnace, Vbecause the small content of carbon of these substances would render them unfit for casting. Therefore this known furnace can only be used for producing cast-ing iron from pig-iron andwaste cast iron.

The object of the present invention is to Y render the furnace capable of producing casting iron from scrap iron and this is accompllshed by arranging an ordinary cupola furv nace instead of the usual shaft before the.

reverberatory furnace and connect-ing the two furnaces so that the molten 'substance or metal fiows directly from the cupola furnace into the reverberatory furnace, while the hot gases from the reverberatory furnace flow out through the cupola furnace. By this arrangement, in which a considerable amount f ofthe heat required for smelting is supplied by the hot gases that are conducted off from the reverberatory furnaceland in which these hot gases also effect the gasification of the coke, it is possible to adjust the quantity ofl the coke requiredfor smelting, to the exact amount needed for obtaining the desired car bon content in the molten metal. vAnother possibility. of the new arrangement, which 5 required to give the' iron the best possible"v mechanical qualities is ensured. The effect of the heat of the hot gases of the reverbera-V tory furnace and cupola furnace is enhanced by causing them to pass through a preheater 5 in which the air of combustion is heated before it passes into the reverberatory furnace.

The invention is illustrated by way of eX- ample in the drawing in which Fig. l is a vertical transverse section,

Fig. 2 a vertical longitudinal section, Fig 3 a horizontal section and Fig. 4 a top view of the new furnace which consists of a cupola. furnace a of an ordinary type into which the metal to be smelted and the addition of coke is vintroduced from a gallery or the like b. The iron which is melted and has its content of carbonA increased in this furnace b flows through the channel or conduite into the reverberatory furnace Z in which it is'heated to' a ltemperature that is 65 higher than the temperature ordinarily obtained in the cupola furnace. The discharge of the molten iron takes place through the discharge aperture or tap hole e. Air and fuel or oil are introduced into the reverberatory furnace atf. The hot gases pass through the conduit c into the shaft of the cupola furnace a and thence, together with the gases produced by the combustion of the coke to thepreheater g, in which the gases `from the furnaces and the air, that enters at 711low pasteach other in separate conduits inopposite directions and the furnace gases impart their heat to the air, which, after it has passed through the preheater is con` ducted by the pipe i to the reverberatory fur- The wind or draft required for combustion in the cupola furnace is blown into the same through the wind nozzles la. The liquid slag formed during the smeltin processis collected in a slag collector -Z w ich is situated opposite the metal discharge channel e.- i

l. Method of smelting low carbon cast' 90 iron having a'definite carbon content in a xcombined cupola andreverberatory furnace, which consists in melting scrap iron, lWith carbonaceous material in the cupola furnace by flue gases drawn from the reverberatory furnace and running the melted iron into the reverberatory furnace and subjecting the same to greater heat therein, thecarbon content being regulated by measurement of quantity of coke in the cupola furnace.

2. Method according to claim 1 in which the molten iron is superlfeated in the reverberatory furnace to a suicient temperature -Y to ensure a. ne distribution of the chiey in eutectic form.

y In testimony whereo nature.

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fI have amxed my Sig! FRITZ WsT. 

